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Related papers: Simple variational approaches to quantum wells

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Conventional quantum chemical solvation theories are based on the mean-field embedding approximation. That is, the electronic wavefunction is calculated in the presence of the mean field of the environment. In this paper a direct quantum…

Chemical Physics · Physics 2009-11-13 Takeshi Yamamoto

An infinite sequence of potential well functions is considered. A trial wavefunction is used with the Schr$\ddot{\text{o}}$dinger equation to obtain an approximate ground state energy for each potential well function. We obtain an…

Quantum Physics · Physics 2018-03-07 Rodney O. Weber

With an ever-expanding ecosystem of noisy and intermediate-scale quantum devices, exploring their possible applications is a rapidly growing field of quantum information science. In this work, we demonstrate that variational quantum…

Quantum Physics · Physics 2021-07-16 Johannes Jakob Meyer , Johannes Borregaard , Jens Eisert

A variational calculus method is applied for hydrogen-like impurities states and exciton states in AlGaAs/GaAs quantum wells within the effective masses approach. The hamiltonian is separated into radial and transversal parts to be…

Materials Science · Physics 2014-02-21 A. Gubanov , G. F. Glinskii

The three-dimensional nonlinear dynamics of an electron gas in a semiconductor quantum well is analyzed in terms of a self-consistent fluid formulation and a variational approach. Assuming a time-dependent localized profile for the fluid…

Plasma Physics · Physics 2015-06-05 F. Haas

Different features of a potential in the form of a Gaussian well have been discussed extensively. Although the details of the calculation are involved, the general approach uses a variational method and WKB approximation, techniques which…

Quantum Physics · Physics 2015-05-20 Saikat Nandi

We propose to perform amplitude estimation with the help of constant-depth quantum circuits that variationally approximate states during amplitude amplification. In the context of Monte Carlo (MC) integration, we numerically show that…

Quantum Physics · Physics 2022-03-23 Kirill Plekhanov , Matthias Rosenkranz , Mattia Fiorentini , Michael Lubasch

Optimization of unitary transformations in Variational Quantum Algorithms benefits highly from efficient evaluation of cost function gradients with respect to amplitudes of unitary generators. We propose several extensions of the…

Quantum Physics · Physics 2022-01-12 Artur F. Izmaylov , Robert A. Lang , Tzu-Ching Yen

Variational quantum algorithms are considered to be appealing applications of near-term quantum computers. However, it has been unclear whether they can outperform classical algorithms or not. To reveal their limitations, we must seek a…

Quantum Physics · Physics 2020-12-15 Kosuke Mitarai , Yasunari Suzuki , Wataru Mizukami , Yuya O. Nakagawa , Keisuke Fujii

Solving optimisation problems is a promising near-term application of quantum computers. Quantum variational algorithms leverage quantum superposition and entanglement to optimise over exponentially large solution spaces using an…

Quantum Physics · Physics 2022-10-13 Edric Matwiejew , Jason Pye , Jingbo B. Wang

We propose a variational perturbation method based on the observation that eigenvalues of each parity sector of both the anharmonic and double-well oscillators are approximately equi-distanced. The generalized deformed algebra satisfied by…

High Energy Physics - Theory · Physics 2008-11-26 Hyeong-Chan Kim , Jae Hyung Yee

We compare two alternative expansions for finite attractive wells. One of them is known from long ago and is given in terms of powers of the strength parameter. The other one is based on the solution of the equations of the…

Quantum Physics · Physics 2016-09-06 Paolo Amore , Francisco M. Fernández

A new family of 2-component vector-valued coherent states for the quantum particle motion in an infinite square well potential is presented. They allow a consistent quantization of the classical phase space and observables for a particle in…

Quantum Physics · Physics 2009-11-13 P. L. Garcia de Leon , J. P. Gazeau , J. Queva

One examines the infinitely deep quantum cavity, also known as the quantum infinite square well, within the framework of the real Hilbert space. The solutions are considered in terms of complex wave functions, and also in terms of…

Quantum Physics · Physics 2026-02-19 Sergio Giardino

We investigate quantum tunneling in smooth symmetric and asymmetric double-well potentials. Exact solutions for the ground and first excited states are used to study the dynamics. We introduce Wigner's quasi-probability distribution…

Quantum Physics · Physics 2011-08-11 Dimitris Kakofengitis , Ole Steuernagel

Discrete PT-symmetric square wells are studied. Their wave functions are found proportional to classical Tshebyshev polynomials of complex argument. The compact secular equations for energies are derived giving the real spectra in certain…

Quantum Physics · Physics 2009-11-13 Miloslav Znojil

Gamow's approach to exponential decay of meta-stable particles via complex 'eigenvalues' (resonances) of a Hamiltonian is scrutinized. We explain the sense in which the non-square-integrable 'eigenfunctions' that belong to these resonances…

Mathematical Physics · Physics 2009-09-18 Robert Grummt

We introduce variational methods for finding approximate eigenfunctions and eigenvalues of quantum Hamiltonians by constructing a set of orthogonal wave functions which approximately solve the eigenvalue equation.

Mathematical Physics · Physics 2013-07-16 Farrokh Atai , Jens Hoppe , Mariusz Hynek , Edwin Langmann

Finite difference method and finite element method are popular methods for solving groundwater flow equations. This paper presents a new method that uses gradually varied functions to solve such equation. In this paper, we have established…

Numerical Analysis · Mathematics 2012-10-17 Li Chen , Xun-Hong Chen

An asymmetric double-well potential is considered, assuming that the minima of the wells are quadratic with a frequency $\omega$ and the difference of the minima is close to a multiple of $\hbar \omega$. A WKB wave function is constructed…

Quantum Physics · Physics 2011-04-13 Dae-Yup Song